Re: [PHP] Do defined variables exist at application scope, or session scope?
On Sat, Dec 27, 2008 at 12:54 AM, Murray wrote: > Hi Larry, > > You're absolutely right, I'm talking about constants rather than variables. > > I guess in my very crude way, I'm trying to ask about the following: > > UserA goes to the site via index.php, which defines several helpful > constants. > > So do UserB through UserF. > > UserG, however, first arrives at the site on help.php. > > Because UserA, UserB, UserC etc have been to index.php, which has now been > executed, are the constants available with their values in help.php, even > though UserG, in particular, started in the application at this point? > > So, another way of putting it, do these constants live for the life of the > application per se (ie, presumably until the server is restarted etc), or > will code in help.php be unable to access the values of defined constants > for this particular user because they were not at index.php first? no, global variables do not persist at a session level. you could easily discover this with a simple test (following code untested :)). testDefineScope1.php
Re: [PHP] Do defined variables exist at application scope, or session scope?
Hi Larry, You're absolutely right, I'm talking about constants rather than variables. I guess in my very crude way, I'm trying to ask about the following: UserA goes to the site via index.php, which defines several helpful constants. So do UserB through UserF. UserG, however, first arrives at the site on help.php. Because UserA, UserB, UserC etc have been to index.php, which has now been executed, are the constants available with their values in help.php, even though UserG, in particular, started in the application at this point? So, another way of putting it, do these constants live for the life of the application per se (ie, presumably until the server is restarted etc), or will code in help.php be unable to access the values of defined constants for this particular user because they were not at index.php first? Many thanks for your reply, M is for Murray On Sat, Dec 27, 2008 at 5:00 PM, Larry Garfield wrote: > On Friday 26 December 2008 11:54:30 pm Murray wrote: > > Hi All, > > > > In the index.php file of my application I define several variables, > > including such things as the base path of the app, and the theme path > etc. > > > > Since I use 'define()' to do this, are these variables available to my > app > > regardless of where a particular user enters the app? > > > > So, in starting the app, I define these variables by visiting index.php. > > But if another user gets sent a url to, for example, the help page, when > > they visit it will those variables be available, or will I need to > > explicitly check on each to make sure the variables are defined, because > > the user entered at a different entry point than the 'normal' one? > > > > Note: I will probably do an explicit check anyway, since this seems more > > robust, but I ask to better understand how define works. > > > > Many thanks, > > > > M is for Murray > > Well, there is no such thing as a "defined variable". You are, I presume, > talking about constants. (That's what you get from define().) A global > constant (vis, not a class constant) is "super-global", that is, available > absolutely everywhere after the line of code that defines it has executed. > > So if the user goes to index.php, and the first line defines a constant > DEBUG_LEVEL, then that constant now exists anywhere in any function or > method > for the rest of that page request, period. > > However, if someone goes to help.php then the line in index.php is never > executed (why would it be, since the file was never included?), so the > constant > is not defined. > > Does that make sense? > > -- > Larry Garfield > la...@garfieldtech.com > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > >
Re: [PHP] Do defined variables exist at application scope, or session scope?
On Friday 26 December 2008 11:54:30 pm Murray wrote: > Hi All, > > In the index.php file of my application I define several variables, > including such things as the base path of the app, and the theme path etc. > > Since I use 'define()' to do this, are these variables available to my app > regardless of where a particular user enters the app? > > So, in starting the app, I define these variables by visiting index.php. > But if another user gets sent a url to, for example, the help page, when > they visit it will those variables be available, or will I need to > explicitly check on each to make sure the variables are defined, because > the user entered at a different entry point than the 'normal' one? > > Note: I will probably do an explicit check anyway, since this seems more > robust, but I ask to better understand how define works. > > Many thanks, > > M is for Murray Well, there is no such thing as a "defined variable". You are, I presume, talking about constants. (That's what you get from define().) A global constant (vis, not a class constant) is "super-global", that is, available absolutely everywhere after the line of code that defines it has executed. So if the user goes to index.php, and the first line defines a constant DEBUG_LEVEL, then that constant now exists anywhere in any function or method for the rest of that page request, period. However, if someone goes to help.php then the line in index.php is never executed (why would it be, since the file was never included?), so the constant is not defined. Does that make sense? -- Larry Garfield la...@garfieldtech.com -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] Do defined variables exist at application scope, or session scope?
Hi All, In the index.php file of my application I define several variables, including such things as the base path of the app, and the theme path etc. Since I use 'define()' to do this, are these variables available to my app regardless of where a particular user enters the app? So, in starting the app, I define these variables by visiting index.php. But if another user gets sent a url to, for example, the help page, when they visit it will those variables be available, or will I need to explicitly check on each to make sure the variables are defined, because the user entered at a different entry point than the 'normal' one? Note: I will probably do an explicit check anyway, since this seems more robust, but I ask to better understand how define works. Many thanks, M is for Murray
